package com.tuling.tulingmall.util;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * @author ：图灵学院
 * @date ：Created in 2020/2/21
 * @version: V1.0
 * @slogan: 天下风云出我辈，一入代码岁月催
 * @description:
 **/
public class VerifyCodeImgUtil {
    /**
     * 创建验证码
     */
    public static VerifyCodeInfo createVerifyCode() {
        int width = 80;
        int height = 32;
        //create the image
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        // set the background color
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, width, height);
        // draw the border
        g.setColor(Color.black);
//        g.drawRect(0, 0, width - 1, height - 1);
        // create a random instance to generate the codes
        Random rdm = new Random();
        // make some confusion
//        for (int i = 0; i < 50; i++) {
//            int x = rdm.nextInt(width);
//            int y = rdm.nextInt(height);
//            g.drawOval(x, y, 0, 0);
//        }
        // generate a random code
        String verifyCode = generateVerifyCode(rdm);
        g.setColor(new Color(0, 100, 0));
        g.setFont(new Font("Candara", Font.BOLD, 24));
        g.drawString(verifyCode, 8, 24);
        g.dispose();
        //把验证码存到redis中
        Integer result = calc(verifyCode);
        if (result == null) {
            return null;
        }
        //输出结果
        return new VerifyCodeInfo(image,result);
    }

    private static Integer calc(String exp) {
        try {
            ScriptEngineManager manager = new ScriptEngineManager();
            ScriptEngine engine = manager.getEngineByName("JavaScript");
            return (Integer)engine.eval(exp);
        }catch(Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    private static char[] ops = new char[] {'+', '-', '*'};
    /**
     * + - *
     * */
    private static String generateVerifyCode(Random rdm) {
        int num1 = rdm.nextInt(10);
        int num2 = rdm.nextInt(10);
        int num3 = rdm.nextInt(10);
        char op1 = ops[rdm.nextInt(3)];
        char op2 = ops[rdm.nextInt(3)];
        String exp = ""+ num1 + op1 + num2 + op2 + num3;
        return exp;
    }

    public static class VerifyCodeInfo{
        private BufferedImage bufferedImage;
        private Integer result;

        public VerifyCodeInfo(BufferedImage bufferedImage,Integer result){
            this.result = result;
            this.bufferedImage = bufferedImage;
        }

        public BufferedImage getBufferedImage() {
            return bufferedImage;
        }

        public void setBufferedImage(BufferedImage bufferedImage) {
            this.bufferedImage = bufferedImage;
        }

        public Integer getResult() {
            return result;
        }

        public void setResult(Integer result) {
            this.result = result;
        }
    }
}
